[INFO] fetching crate serde_tuple 0.5.0...
[INFO] checking serde_tuple-0.5.0 against try#894d32a5432c6a6461bb2aac7c3d5f2e87dce83f for pr-77015
[INFO] extracting crate serde_tuple 0.5.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate serde_tuple 0.5.0 on toolchain 894d32a5432c6a6461bb2aac7c3d5f2e87dce83f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate serde_tuple 0.5.0
[INFO] finished tweaking crates.io crate serde_tuple 0.5.0
[INFO] tweaked toml for crates.io crate serde_tuple 0.5.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate crates.io crate serde_tuple 0.5.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded syn v0.15.36
[INFO] [stderr]   Downloaded serde_tuple_macros v0.5.0
[INFO] [stderr]   Downloaded serde_derive v1.0.92
[INFO] [stderr]   Downloaded quote v0.6.12
[INFO] [stderr]   Downloaded ryu v0.2.8
[INFO] [stderr]   Downloaded serde v1.0.92
[INFO] [stderr]   Downloaded serde_json v1.0.39
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 63b159b465080acdfd1c6bfd728778368c542142ad07cce319be07d47f36038d
[INFO] running `Command { std: "docker" "start" "-a" "63b159b465080acdfd1c6bfd728778368c542142ad07cce319be07d47f36038d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "63b159b465080acdfd1c6bfd728778368c542142ad07cce319be07d47f36038d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63b159b465080acdfd1c6bfd728778368c542142ad07cce319be07d47f36038d", kill_on_drop: false }`
[INFO] [stdout] 63b159b465080acdfd1c6bfd728778368c542142ad07cce319be07d47f36038d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6f4652d582344d6719822fd7f6f4fd38aaedf2a7cfb248d44e733cdfddf7c9cf
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "6f4652d582344d6719822fd7f6f4fd38aaedf2a7cfb248d44e733cdfddf7c9cf", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling serde v1.0.92
[INFO] [stderr]    Compiling ryu v0.2.8
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]    Compiling serde_tuple_macros v0.5.0
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking serde_tuple v0.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::borrow::Cow`
[INFO] [stdout]  --> examples/simple.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::borrow::Cow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ok`
[INFO] [stdout]   --> examples/simple.rs:23:8
[INFO] [stdout]    |
[INFO] [stdout] 23 | struct Ok;
[INFO] [stdout]    |        ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 47.20s
[INFO] running `Command { std: "docker" "inspect" "6f4652d582344d6719822fd7f6f4fd38aaedf2a7cfb248d44e733cdfddf7c9cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f4652d582344d6719822fd7f6f4fd38aaedf2a7cfb248d44e733cdfddf7c9cf", kill_on_drop: false }`
[INFO] [stdout] 6f4652d582344d6719822fd7f6f4fd38aaedf2a7cfb248d44e733cdfddf7c9cf